Analysis of ascending spinal tract degeneration in cervical spondylotic myelopathy using 3D anisotropy contrast single-shot echo planar imaging on a 3.0-T system.

Abstract

The authors assessed the role of 3D anisotropy contrast (3DAC) in evaluating specific ascending tract degeneration in patients with cervical spondylotic myelopathy (CSM). The authors studied 10 patients (2 women, 8 men; mean age 59.8 ± 14.6 years) with CSM and spinal cord compression below the C2-3 disc level, as well as 10 healthy control individuals (3 women, 7 men; mean age 42.0 ± 24.1 years). Images of the cervical cord at the C2-3 level were obtained using a 3.0-T MR imaging system. Three-dimensional anisotropy contrast imaging clearly made possible tract-by-tract analysis of the fasciculus cuneatus, fasciculus gracilis, and spinocerebellar tract. Tract degeneration identified using 3DAC showed good correlation with a decline in fractional anisotropy. Degeneration of the fasciculus gracilis detected by "vector contrast" demonstrated a good correlation with Nurick grades. The study unambiguously demonstrated that 3DAC imaging is capable of assessing ascending tract degeneration in patients with CSM. Degeneration of an individual tract can be easily identified as a vector contrast change on the 3DAC image, a reflection of quantitative changes in anisotropism, similar to fractional anisotropy. Excellent correlation between Nurick grades and fasciculus gracilis degeneration suggests potential application of 3DAC imaging for tract-by-tract clinical correlation.